Although babies don’t say their first words until they’re about one year old, Kuhl and her colleagues made an interesting discovery when they recently became the first researchers in the world to put much younger babies in a magnetoencephalography brain scanner.

When the researchers played seven-month-old babies vowel sounds, Kuhl said, they expected to see activity in the auditory regions of the brain — the parts that babies use to listen.

The auditory brain regions lit up, but that wasn't all. "The surprise came in the activation in motor planning regions of the brain. The areas of the brain that children use to talk," Kuhl said.

That suggests that babies who won’t be talking for months are already trying to figure out the mechanics of language: how to get their bodies to make those same words. "So when babies hear us talk the main thing they want to do is talk back, take turns," Kuhl said.

She said the research sheds more light on the importance of talking directly to babies long before they’re able to respond.

Several weeks ago, the American Academy of Pediatrics recommended that parents read to their babies daily from birth.

Kuhl says you don’t need to read infants scientific papers to help their brains develop. In fact, Kuhl says, babies’ brains respond best to "parentese," the typical sing-song, highly-enunciated, slow phrasing that caregivers reflexively use when speaking to babies.